Optical image stabilization (ois) unit of a camera module

ABSTRACT

An Optical Image Stabilization (OIS) unit including a base; a holder module comprising an outer blade spaced apart from the base, a bobbin disposed in the outer blade, and a spring member connecting the outer blade and the bobbin; a first coil disposed on the bobbin; a magnet configured to interact with the first coil; a second coil configured to interact with the magnet; a wire coupled with the holder module; a first connection unit fixing a first end portion of the wire; and a buffer portion disposed on a part of the wire and comprising an adhesive material. Further, in a direction perpendicular to the wire, a maximum width of the buffer portion is greater than a maximum width of the first connection unit.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of copending application Ser. No.16/919,881, filed on Jul. 2, 2020, which is a Continuation of U.S.application Ser. No. 16/357,801 filed Mar. 19, 2019 (now U.S. Pat. No.10,725,314 issued Jul. 28, 2020), which is a Continuation of U.S.application Ser. No. 15/094,592 filed Apr. 8, 2016 (now U.S. Pat. No.10,274,746B issued Apr. 30, 2019), which is a Continuation of U.S.application Ser. No. 14/583,422 filed on Dec. 26, 2014 (now U.S. Pat.No. 9,332,187 issued on May 3, 2016), which is a Continuation of U.S.application Ser. No. 14/203,263 filed on Mar. 10, 2014 (now U.S. Pat.No. 8,953,096 issued on Feb. 10, 2015), which is a Continuation of U.S.application Ser. No. 13/550,057 filed on Jul. 16, 2012 (now U.S. Pat.No. 8,698,952 issued on Apr. 15, 2014), which claims priority to KoreanPatent Application No. 10-2011-0112190 filed on Oct. 31, 2011 and KoreanPatent Application No. 10-2011-0115804 filed on Nov. 8, 2011, the entiredisclosures of which are expressly incorporated by reference herein intheir entireties.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a camera module.

Background of the Related Art

A camera module mounted on a small-sized electronic product may befrequently subject to a shock while in use. The camera module may beminutely shaken by a user's hand shaking during photographing. In viewof the above problems, there is recently being disclosed a camera modulehaving hand-shaking prevention means.

For example, Korean Registration Patent No. 10-0741823 (registered onJul. 16, 2007) discloses a method of installing a gyro sensor IC or anangular velocity sensor within a device on which a camera module ismounted, such as a mobile phone in order to correct a hand shakingphenomenon.

If an additional angular velocity sensor is provided as described above,an additional sensor must be provided in order to implement thehand-shaking prevention function. Accordingly, there are problems inthat manufacture costs are increased and an additional space where ahand-shaking prevention device will be constructed and installed must beprovided in addition to the camera module.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a camera modulehaving an optical image stabilizer function.

A camera module according to the present invention includes a firstPrinted Circuit Board (PCB) configured to have an image sensor mountedthereon; a housing unit disposed over the first PCB; a holder modulespaced apart from a bottom surface within the housing unit at a specificinterval and configured to have first coils wound on its outercircumferential face and to include at least lens therein; a second PCBcombined with the bottom surface of the holder module; a third PCBdisposed over the holder module; a plurality of wire springs eachconfigured to have one end connected to the second PCB and the other endconnected to the third PCB; and buffer units provided at the connectionunits of the wire springs and the third PCB and configured to surroundthe connection units of the wire springs and the third PCB.

It is preferred that each of the buffer units include at least oneinjection hole formed to penetrate the third PCB around a through holeto which the wire spring is connected and a second wire spring throughhole formed to penetrate the housing unit in a form taped downwardly sothat the second wire spring through hole is placed on the same axis as athrough hole formed in the third PCB and formed to communicate with theinjection hole through an upper opening.

A camera module according to an exemplary embodiment of the presentinvention preferably may include an adhesive substance injected into thesecond wire spring through hole through the injection hole.

Furthermore, the wire springs and the third PCB are coupled through thethrough hole. Here, it is preferred that the wire springs be connectedto the top and bottom surfaces of the third PCB through the through holeby a connection substance and the connection substance include aconductive substance, such as lead.

Furthermore, it is preferred that each of the buffer units include apair of injection holes formed to penetrate the third PCB on both sidesof a first wire spring through hole to which the wire spring is solderedand a second wire spring through hole formed to penetrate the housingunit in a form taped downwardly so that the second wire spring throughhole is placed on an axis identical with the first wire spring throughhole of the third PCB and to communicate with the pair of injectionholes through an upper opening.

Furthermore, a camera module according to an exemplary embodiment of thepresent invention further includes an adhesive substance injected intothe second wire spring through hole through the pair of injection holes.It is preferred that the adhesive substance cover all the connectionunits formed within the second wire spring through hole and on the topof the third PCB. Here, the adhesive substance preferably may be epoxy.

It is preferred that the second wire spring through hole include theupper opening provided in the housing unit in a funnel form tapeddownwardly and a wire spring support hole provided axially with thethrough hole.

The second wire spring through hole may have a diameter equal to orgreater than the through hole.

It is preferred that the housing unit include a first housing disposedon the upper side of the first PCB; a second housing disposed on theupper side of the first housing and configured to have the third PCBdisposed thereon; first and second permanent magnets interposed betweenthe first and the second housings; and yoke each disposed between thefirst and the second permanent magnets or placed on the inside of thefirst and the second housing and configured to transfer magnetic forceto the holder module.

It is preferred that the yoke have a central part protruded toward theholder module.

The second housing and the third PCB preferably may be fixed by adouble-sided tape.

Furthermore, a camera module according to an exemplary embodiment of thepresent invention preferably may include a shield can formed to have athrough hole at a position where the connection unit of the third PCBand the wire spring corresponds to a lens module and to surround thehousing unit.

The holder module includes an outer blade formed to have first coilswound on its outer faces; a bobbin elastically supported by an elasticmember on the upper side of the outer blade, disposed to be movable upand down within the outer blade, and configured to have a second coilwound on its outer circumferential face and to have at least one lensinstalled therein; and upper and lower elastic members disposed onrespective upper and lower sides of the bobbin and configured toelastically support the bobbin against the outer blade. A space unit maybe formed at the center of each of the first coils so that magneticforce is applied toward the second coil.

The wire springs preferably may be made of metal material and conductivewith the second and the third PCBs.

The number of the wire springs preferably may be at least 6 so that apower source of two polarities for auto-focusing control and a powersource of four polarities for optical image stabilizer are supplied tothe holder module through connection between the wire springs and thesecond and the third PCBs.

Furthermore, four pairs of the wire springs having the same length maybe disposed at the respective corners of the holder module.

A camera module according to another exemplary embodiment of the presentinvention includes a first Printed Circuit Board (PCB) configured tohave an image sensor mounted thereon; a housing unit disposed over thefirst PCB; a holder module spaced apart from a bottom surface within thehousing unit at a specific interval and configured to have first coilswound on its outer circumferential face and to include at least lenstherein, a second PCB combined with the bottom surface of the holdermodule; a third PCB disposed over the holder module; and a plurality ofwire springs each configured to have one end connected to the second PCBand the other end connected to the third PCB, wherein the wire springsand the third PCB are connected through through holes formed topenetrate the third PCB so that the top and bottom surfaces of the thirdPCB are connected by a connection substance.

Meanwhile, a camera module according to the present invention mayfurther include surface processing units formed at both ends of each ofthe wire springs and configured to increase bonding force between thewire springs and the second and the third PCBs.

The surface processing unit may be coarsely formed by polishing asurface of the wire spring or may be formed by removing the coating filmof the wire spring.

In accordance with the present invention, the wire springs can be firmlyconnected to the connection units of the PCBs because the buffer unitsfor absorbing load repeatedly applied to the wire springs are provided.

Furthermore, although excessive force is applied to the wire springs ina process of assembling the lens module, the buffer units can absorb theexcessive force. Accordingly, an assembly property can be improved, andthe loss of parts due to poor assembly can be minimized.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects and advantages of the invention can be more fullyunderstood from the following detailed description taken in conjunctionwith the accompanying drawings in which:

FIG. 1 is a schematic plan view of a camera module according to anembodiment of the present invention;

FIG. 2 is a sectional view of the camera module taken along line A-A ofFIG. 1;

FIGS. 3 and 4 are side views of the camera module according to theembodiment of the present invention;

FIG. 5 is an enlarged view of a part B of FIG. 2 according to a firstembodiment of the present invention;

FIG. 6 is an enlarged view of a part B of FIG. 2 according to a secondembodiment of the present invention;

FIG. 7 is an enlarged view of a part B of FIG. 2 according to third andfourth embodiments of the present invention;

FIG. 8 is a diagram showing shows the surface processing units of a wirespring according to the third embodiment of the present invention; and

FIG. 9 is a diagram showing shows the surface processing units of a wirespring according to a fourth embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, some exemplary embodiments of the present invention aredescribed in detail with reference to the accompanying drawings.

FIG. 1 is a schematic plan view of a camera module according to anembodiment of the present invention, FIG. 2 is a sectional view of thecamera module taken along line A-A of FIG. 1, FIGS. 3 and 4 are sideviews of the camera module according to the embodiment of the presentinvention, and FIG. 5 is an enlarged view of a part B of FIG. 2according to a first embodiment of the present invention.

As shown in FIG. 1 showing the schematic plan view and FIG. 2 showingthe schematic side view of line A-A in FIG. 1, the camera moduleaccording to the present invention includes a first Printed CircuitBoard (hereinafter referred to as a PCB) 10, a housing unit 20, a holdermodule 30, a second PCB 40, a third PCB 50, wire springs 60, and bufferunits 100.

It is preferred that an image sensor 11 be mounted approximately on thecentral part of the first PCB 10. Elements for driving the image sensor11 may be disposed in the first PCB 10 or a plurality of terminal unitsfor supplying power and outputting information from the image sensor 11may be provided in the first PCB 10.

The housing unit 20 is disposed over the first PCB 10, and it forms theframework of the camera module. In accordance with an exemplaryembodiment of the present invention, the housing unit 20 includes afirst housing 21, a second housing 22, pairs of first and secondpermanent magnets 23 and 24, and a plurality of yokes 25.

The first housing 21 is a base and is disposed on the top of the firstPCB 10 and spaced apart from the image sensor 11 at a specific interval.A filter member for filtering an image phase incident on the imagesensor 11 may be further included in the first housing 21 as occasiondemands.

The second housing 22 is disposed on the top of the first housing 21 andis configured to cover the first housing 21. An opening is formedapproximately at the center of the second housing 22 so that an imagecan be transferred to the image sensor 11. The third PCB 50 is adheredand fixed to the upper lateral face of the second housing 22 using afixing member to be described later, such as a double-sided tape or anadhesive, but not limited thereto. In some embodiments, however, anadditional third housing, such as a casing or a shield can, may beprovided, and the third PCB 50 may be fixed to the inside of theadditional third housing using the fixing member according to a productdesign. If the third housing is provided, the third housing may pressand support the third PCB 50 without an additional fixing member.

The first and the second permanent magnets 23 and 24 are interposedbetween the first and the second housings 21 and 22 and are configuredto apply magnetic force to the holder module 30. It is preferred thatthe first and the second permanent magnets 23 and 24 have the same size.Furthermore, the first and the second permanent magnets 23 and 24 andthe yoke 25 may be disposed on the inside of the first and the secondhousing 21 and 22, if possible, within a design tolerance limit.

Meanwhile, if the size of the first and the second permanent magnets 23and 24 is increased, OIS driving is increased even by low current. Ifthe first and the second permanent magnets 23 and 24 are configured tohave a specific size, OIS driving is increased as current flowing intofirst and the second coils 31 a to 31 d and 32 a disposed at positionscorresponding to the first and the second permanent magnets 23 and 24 isincreased. Consequently, OIS driving becomes better according to anincrease of the first and the second permanent magnets 23 and 24, but itis preferred that the first and the second permanent magnets 23 and 24have an optimized size within a design tolerance limit.

Each of the yokes 25 is interposed between each of the pairs of firstand the second permanent magnets 23 and 24. Furthermore, the centralportion of the yoke 25 is configured to have a protruded shape so thatthe pair of first and second permanent magnets 23 and 24 may applymagnetic force to the internal space of the holder module 30. It ispreferred that the yoke 25 be configured to the same width as the pairof first and second permanent magnets 23 and 24, the center of the yoke25 be protruded in a specific size, and the pair of first and secondpermanent magnets 23 and 24 and the yoke 25 have an approximately ‘T’shape.

The holder module 30 is spaced apart from the bottom surface of theinside of the housing unit 20 and is formed of an outer blade 31 and abobbin 32. The holder module 30 may perform a pendulum movement in thefront/rear, left/right, and diagonal directions with it dangled from thewire springs 60.

Spring members 35 and 36 are provided in the upper and lower parts ofthe outer blade 31, respectively. The outer blade 31 is elasticallysupported by the spring member 35 so that the bobbin 32 is moved up anddown.

As shown in FIG. 1, a total of four first coils 31 a to 31 d are woundon the four outer faces of the outer blade 31, respectively, and thecentral part of each of the four outer faces of the outer blade 31 onwhich the first coils 31 a to 31 d are wound is perforated without acoil. Each of the yokes 25 is disposed at a position corresponding tothe perforated space unit, and thus the yoke 25 may be partiallyinserted into the space unit.

The second PCB 40 may be fixed to the bottom of the outer blade 31 usinga fixing member 33, such as a double-sided tape or an adhesive. Theouter blade 31 is dangled from the plurality of wire springs 60 so thatthe outer blade 31 can move in the front/rear and left/right directionsor in a diagonal line according to an interaction between the magneticforce of the first and the second permanent magnets 22 and 23 and thefirst coils 31 a, as indicated by an arrow of FIG. 2. Furthermore, theouter blade 31 is spaced apart from the bottom surface of the firsthousing 21 at a specific interval.

Furthermore, a plurality of spring through holes 37 may be provided inthe outer blade 31 so that the wire springs 60 are connected to thesecond PCB 40 through the spring through holes 37.

The bobbin 32 is disposed within the outer blade 31 so that it ismovable up and down. At least one lens 34 is installed within the bobbin32. The second coil 32 a is wound on the outer circumferential face ofthe bobbin 32. The second coil 32 a performs an operation of raising upand lowering the bobbin 32 through an interaction with the magneticforce applied through the perforated spaces without the first coils 31 ato 31 d of the outer blade 31 through the yokes 25. As the size of theyoke 25 increases, AF driving may become better, but may be changedaccording to an optimal design value. It is possible to automaticallycontrol the focus of an image transferred to the image sensor 11 throughthe raising action of the bobbin 32.

The second PCB 40 is disposed at the bottom surface of the outer blade31 as described above and is connected to the wire springs 60 so that itcan supply a power source to the first and the second coils 31 a to 31 dand 32 a. This connection method may include any method if soldering orother conductive substances may be used. That is, the connection unitsw′ of the second PCB 40 are connected to the first coils 31 a to 31 d,respectively, and the second coil 32 a, as shown in, FIG. 2. Thus, apower source supplied through the wire springs 60 is transferred to thefirst and the second coils 31 a to 31 d and 32 a, thus formingelectromagnetic force.

Here, the second coil 32 a may be directly connected to the second PCB40, or the second coil 32 a may be connected to the lower spring 36 andthe lower spring 36 may be then connected to the second PCB 40 as shownin FIG. 2.

The third PCB 50 is fixed to the top of the second housing 22 using thefixing member, such as a double-sided tape or an adhesive member, asdescribed above. A power source transferred through the terminal unit 52of the third PCB 50 connected to the first PCB 10 is transferred to thesecond PCB 40 through the wire springs 60 connected to the second PCB40. This connection method may include any method if soldering or otherconductive substances may be used.

The third PCB 50 may be provided to cover the walls of the first and thesecond housings 21 and 22 on one side, as shown in FIGS. 3 and 4. Here,a window 55 may be formed in a surface of the third PCB 50 where thethird PCB 50 faces the first and the second permanent magnets 23 and 24and the yoke 25 in order to avoid interference therebetween.

The window 55 functions to prevent the third PCB 50 from beinginfluenced by coupling portions because the first and the secondpermanent magnets 23 and 24 and the yoke 25 are directly adhered to ashield can 70 (described later) by using the fixing means, such asepoxy.

Meanwhile, a flexible PCB (FPCB), a PCB, or a rigid FPCB integrationtype (R-FPCB) may be used as each of the second PCB 40 and the third PCB50, but not limited thereto. Any board may be used as the second PCB 40and the third PCB 50 if the board enables electrical connection.

Each of the wire springs 60 has both ends connected to the second andthe third PCBs 40 and 50. Here, one end of the wire spring 60 isconnected to a pad 51 formed in the third PCB 50 as shown in FIG. 5. Athrough hole 53 through which the wire spring 60 passes is formed at thecenter of the pad 51. In this case, a connection method may include anymethod if soldering or other conductive substances may be used.Meanwhile, a Solder Register (SR) is provided around the pad 51, thusprotecting a surface of the third PCB 50. The area of the pad 51 may beconnected by opening the SR so that the area is conductive.

The wire spring 60 connected at the pad 51 as described above suppliesthe power source from the terminal unit 52 to the second PCB 40, so thatthe first and the second coils 31 a to 31 d and 32 a may interact withthe first and the second permanent magnets 23 and 24.

Furthermore, the other end of the wire spring 60 is connected to thesecond PCB 40, provided at the bottom surface of the outer blade 31,through the spring through hole 37 formed in the outer blade 31, asshown in FIG. 2. As in the third PCB 50, the other end of the wirespring 60 is connected at a pad (not shown) formed in the second PCB 40,although not shown. A through hole (not shown) through which the wirespring 60 passes is formed at the center of the pad (not shown). In thiscase, a connection method may include any method if soldering or otherconductive substances may be used. In this construction, the outer blade31 may be dangled from the wire springs 60 and may be spaced apart fromthe bottom surface of the first housing 21. In this case, the outerblade 31 performs a pendulum movement according to an interactionbetween the first coils 31 a to 31 d and the first and the secondpermanent magnets 23 and 24. Accordingly, the vibration of the outerblade 31 due to hand shaking can be corrected by the interaction betweenthe first coils 31 a to 31 d and the first and the second permanentmagnets 23 and 24. To this end, it is preferred that the wire spring 60be made of metal material that has elasticity enough to withstand ashock and conductivity.

Meanwhile, as the thickness of the wire spring 60 is reduced, opticalimage stabilizer motility becomes better even at a low current, but maybe changed according to an optimal design value. It is preferred thatthe thickness of the wire spring 60 be several μm to several hundreds ofμm, more preferably, 1 to 100 μm.

Furthermore, it is preferred that the number of wire springs 60 be atleast six. It is necessary to supply a power source of two polaritiesfor auto-focusing control and a power source of four polarities foroptical image stabilizer to the holder module 30 through connectionbetween the wire springs 60 and the second and the third PCBs 40 and 50.

In accordance with an exemplary embodiment of the present invention, itis preferred that four pairs of the wire springs 60 having the samelength are disposed at the respective corners of the holder module 30 inorder to keep the balance, as shown in FIGS. 1 and 2.

Meanwhile, if an additional third housing, such as the shield can 70, isincluded as shown in FIG. 2, the windows 55 for covering the walls ofthe first and the second housings 21 and 22 are formed in the third PCB50 in order to avoid the coupling parts because the first and the secondpermanent magnets 23 and 24 and the yokes 25 are fixed to the shield can70 using epoxy, as described above.

If the shield can 70 is omitted, the first and the second permanentmagnets 23 and 24 and the yokes 25 may be attached and fixed within thethird PCB 50. In some embodiments, the windows 55 may be formed in thethird PCB 50 as described above, and the first and the second permanentmagnets 23 and 24 and the yokes 25 may be inserted into the windows 55.Reinforcement may be additionally performed outside the third PCB 50using a shielding tape.

Buffer units 100 function to absorb a shock and repeated load applied tothe wire springs 60 by surrounding connection units w where the wiresprings 60 are connected to the third PCB 50.

In accordance with an exemplary embodiment of the present invention,each of the buffer units 100 includes an injection hole 110 and a secondwire spring through hole 120.

The injection hole 110 is formed around the through hole 53 to which thewire spring 60 passing through the third PCB 50 is soldered. Inaccordance with the first embodiment of the present invention, thenumber of injection holes 110 may be one, as shown in FIG. 5.

The second wire spring through hole 120 is provided in the second holder22. The second wire spring through hole 120 includes an upper opening121 and a support hole 122.

The upper opening 121 has a structure that is taped downwardly. It ispreferred that the upper opening 121 have a conical funnel shape that isdownwardly tapered, as shown in FIGS. 5 and 6. The support hole 122 isformed in the same axis as the through hole 53. It is preferred that thesupport hole 122 have a diameter equal to or greater than the throughhole 53.

It is preferred that the through hole 53 have a diameter slightlygreater than the wire spring 60. When the wire spring 60 is connected atthe pad 51 formed in the third PCB 50, a connection substance 101, suchas soldering or another conductive substance, flows out through thethrough hole 53. The connection substance 101 may be connected to thewire spring 60 in the top and bottom surfaces of the third PCB 50, asshown in FIGS. 5 and 6.

It is preferred that the diameter of the support hole 122 be slightlygreater than the diameter of the wire spring 60. The diameter of thesupport hole 122 may be equal to or greater than the diameter of thethrough hole 53. That is, the diameter of the support hole 122 may bedesigned so that the wire spring 60 does not interfere with the secondholder 22 near the support hole 122 through contact with the secondholder 22.

A shown in FIG. 5, an adhesive substance 130 is injected through theinjection hole 110 and then filled in the internal space unit of thesecond wire spring through hole 120. The adhesive substance 130 mayfurther cover the connection unit w of the third PCB 50. The adhesivesubstance 130 filled in the second wire spring through hole 120 mayabsorb a shock and load transferred to the connection unit w of the wirespring 60 and the third PCB 50 and may prevent the wire spring 60 frombeing shaken within the upper opening 121 of the second wire springthrough hole 120. Epoxy may be used as the adhesive substance 130, butnot limited thereto. Any material that may support elasticity throughadhesion may be used as the adhesive substance 130.

In accordance with a second embodiment of the present invention, thebuffer unit 100 may be configured like in the first embodiment, but apair of the injection holes 110 may be provided in the buffer unit 100.In this case, the pair of the injection holes 110 may be disposed onboth sides of the through hole 53 or may be symmetrically disposed eachother, but not limited to the positions.

In this case, the adhesive substance 130 injected through the pair ofinjection holes 110 may fully cover not only the inside of the upperopening 121 of the second wire spring through hole 120, but also theconnection unit w formed on the top of the third PCB 50, as shown inFIG. 4.

In accordance with this construction, there are additional effects thatthe connection unit w of the third PCB 50 exposed at the top can beprevented from being damaged by an external shock and the connectionunit w is insulated.

Meanwhile, in a common assembly process, after the bobbin 32 and theouter blade 31 are combined, the second housing 22, the second and thethird PCBs 40 and 50, and the wire springs 60 are coupled, the bobbin 32including a lens barrel is combined, the first housing 21 is connected,and the first housing 21 is then mounted on the first PCB 10 by using ajig. Alternatively, the permanent magnets and the yokes may be combinedbefore the first housing 21 is connected. The sequence of the aboveassembly may be changed as occasion demands. In other words, theassembly may be directly performed in equipment without a jig. In thisprocess, although force for inserting and combining the bobbin 32including the lens barrel is excessively great and the connection unitsw are adversely affected by the excessive force, the buffer units 100may absorb the excessive force.

In other words, the transformation energy of the buffer unit 100 absorbsload that is generated in the wire spring 60 around the connection unitw of the wire spring 60 and the third PCB 50 and thus pulled in thedirection of gravity and load generated when the wire spring 60 isshaken left and right, as shown in FIGS. 2, 5, and 6.

Accordingly, a problem that the connection task has to be performedagain or that a damaged product cannot be used because the connectionunit w is broken during the assembly process can be avoided. It is thuspossible to produce a reliable camera module.

Surface processing units 1100 are formed at both ends of each of thewire springs 60, thereby improving a coupling property between thesecond and the third PCBs 40 and 50 and the wire spring 60.

In accordance with third and fourth embodiments of the presentinvention, each of the surface processing units 1100 may be coarselyformed by polishing a surface of the wire spring 60 as shown in FIG. 5or may be formed by partially removing a coating film formed on thesurface of the wire spring 60 using a method, such as corrosion, asshown in FIG. 6. If the surface processing unit 1100 is formed asdescribed above, bonding force between lead and the wire spring 60 canbe improved when a soldering process using lead as the connectionsubstance is performed.

Meanwhile, a second wire through hole 120 is provided in the secondholder 22, as shown in FIG. 7. The second wire through hole 120 includesan upper opening 121 and a wire spring support hole 122.

The upper opening 121 has a conical funnel shape that is downwardlytapered. The wire spring support hole 122 is formed on the same axis asthe first wire through hole 53. It is preferred that the wire springsupport hole 122 have a diameter equal to or greater than the first wirethrough hole 53.

Here, the diameter of the first wire through hole 53 may be slightlygreater than the diameter of the wire spring 60. The diameter of thefirst wire through hole 53 may be designed so that, when the wire spring60 is connected to the pad 51 formed in the third PCB 50, a connectionsubstance, such as soldering or other conductive substances, flows downthrough the first wire through hole 53 and the connection substance isthen connected and fixed to the wire spring 60 on the top and bottomsurfaces of the third PCB 50.

Furthermore, the diameter of the wire spring support hole 122 may beslightly greater than the diameter of the wire spring 60. The wirespring support hole 122 may have a diameter equal to or greater than thefirst wire through hole 53. That is, the diameter of the wire springsupport hole 122 may be designed so that the wire spring 60 does notinterfere with the second holder 22 near the support hole 122 throughcontact with the second holder 22.

In accordance with this construction, the wire springs 60 can becombined with the second and the third PCBs 40 and 50 more firmly.Furthermore, a reliability problem (e.g., the separation ordisconnection of the wire springs 60 that may occur owing to externalforce, such as a drop) can be improved.

That is, the surface processing units 1100 increase the frictional forceof the connection units w and w′ between the wire springs 60 and thesecond and the third PCBs 40 and 50, so that the surface processingunits 1100 withstand load in the direction of gravity applied to thewire springs 60 at the connection units w and w′ and load that may occurwhen the wire springs 60 are shaken left and right, as shown in FIGS. 2,8, and 9.

Accordingly, a problem that the connection task has to be performedagain or that a damaged product cannot be used because the connectionunit w is broken during the assembly process can be avoided. It is thuspossible to produce a more reliable camera module.

Meanwhile, the surface processing unit 1100 may be formed only at theend of one side of the wire spring 60, although not shown. That is, thesurface processing unit 1100 may be formed only at the connection unit wwith the third PCB 50 to which heavy load is repeatedly applied or atthe connection unit w′ with the second PCB 40.

Meanwhile, the shield can 70 may be further provided to have a throughhole at a position corresponding to the lens module 30 near theconnection units w of the third PCB 50 and the wire springs 60 andconfigured to surround the housing units 21 and 22. In this case, thethird PCB 50 may be attached and fixed to the inside of the shield can70 as described above. Meanwhile, the shield can 70 is not a requisiteand may be omitted according to constructions of the housing units 21and 22.

Meanwhile, as shown in FIG. 2, in order to fix the shield can 70 to thefirst housing 21, a hook unit 80 may be provided at each of the fourfaces or at one or more faces. The position of the hook unit 80 may bewithin a range in which the center or corner design is allowed. Thenumber of hook units 80 may be one or more.

The hook unit 80 may include a hook 81 protruded into the first housing21 and a hook hole 82 formed to penetrate the shield can 70 facing thehook 81, and an opposite construction is possible as an occasiondemands.

The embodiments of the present invention described above and shown inthe drawings should not be construed as limiting the technical spirit ofthe present invention. The scope of the present invention is restrictedby only the claims, and a person having ordinary skill in the art towhich the present invention pertains may improve and modify thetechnical spirit of the present invention in various forms. Accordingly,the modifications and modifications will fall within the scope of thepresent invention as long as they are evident to those skilled in theart.

1. An Optical Image Stabilization (OIS) unit comprising; a base; aholder module comprising an outer blade spaced apart from the base, abobbin disposed in the outer blade, and a spring member connecting theouter blade and the bobbin; a first coil disposed on the bobbin; amagnet configured to interact with the first coil; a second coilconfigured to interact with the magnet; a wire coupled with the holdermodule; a first connection unit fixing a first end portion of the wire;and a buffer portion disposed on a part of the wire and comprising anadhesive material, wherein, in a direction perpendicular to the wire, amaximum width of the buffer portion is greater than a maximum width ofthe first connection unit.
 2. The OIS unit of claim 1, wherein at leasta portion of the buffer portion is disposed between the first connectionunit and the outer blade.
 3. The OIS unit of claim 1, wherein the springmember comprises an upper spring coupled to an upper portion of thebobbin and a lower spring coupled to a lower portion of the bobbin, andwherein the first connection unit is disposed nearer to the upper springthan the lower spring.
 4. The OIS unit of claim 1, further comprising afirst substrate disposed on the base and comprising a terminal, whereinthe first substrate comprises a first portion disposed on the base and asecond portion bent from the first portion, and wherein the wireconnects the holder module and the first portion of the first substrate.5. The OIS unit of claim 4, wherein the first portion of the firstsubstrate comprises a first surface facing the holder module and asecond surface disposed opposite to the first surface, and wherein thewire is coupled to the second surface of the first portion of the firstsubstrate.
 6. The OIS unit of claim 4, wherein the first substratecomprises a pad disposed on the first portion and a hole disposed in acenter area of the pad, and wherein the wire passes through the hole andis coupled to the pad by a solder.
 7. The OIS unit of claim 6, wherein asolder resistor is disposed on a periphery of the pad to form an outersurface of the first substrate.
 8. The OIS unit of claim 3, furthercomprising a second connection unit fixing a second end portion of thewire, wherein the second connection unit is disposed nearer to the lowerspring than the upper spring.
 9. The OIS unit of claim 8, wherein thefirst connection unit comprises a first solder, and wherein the secondconnection unit comprises a second solder.
 10. The OIS unit of claim 9,wherein at least a portion of the buffer portion is disposed between thefirst solder and the second solder.
 11. The OIS unit of claim 1, whereinthe holder module comprises first, second, third and fourth cornerportions, and wherein the wire is disposed on each of the first, second,third and fourth corner portions of the holder module.
 12. The OIS unitof claim 11, wherein the wire comprises six wires spaced apart from eachother, wherein two wires of the six wires are disposed on the firstcorner portion, and another two wires of the six wires are disposed onthe third corner portion, and wherein the first corner portion and thethird corner portion are disposed opposite to each other based on anoptical axis.
 13. The OIS unit of claim 1, wherein the first coil iselectrically connected with the wire.
 14. The OIS unit of claim 12,wherein the two wires disposed on the first corner portion areelectrically connected with the first coil.
 15. The OIS unit of claim 1,wherein the buffer portion is configured to absorb a shock or loadapplied to the wire,
 16. A camera module, comprising: a printed circuitboard (PCB); an image sensor disposed on the PCB; the OIS unit of claim1 disposed on the PCB; and a lens coupled to the bobbin of the OIS unitand being spaced apart from the image sensor.
 17. A mobile phone,comprising the camera module of claim
 16. 18. An Optical ImageStabilization (OIS) unit comprising; a base; a holder module comprisingan outer blade spaced apart from the base, a bobbin disposed in theouter blade, and a spring member connecting the outer blade and thebobbin; a first coil disposed on the bobbin; a magnet configured tointeract with the first coil; a second coil configured to interact withthe magnet; a wire coupled with the holder module; a first solder fixinga first end portion of the wire; and a buffer portion disposed on a partof the wire and comprising an adhesive material, wherein the firstsolder is disposed within the buffer portion.
 19. The OIS unit of claim18, wherein, in a direction perpendicular to the wire, a maximum widthof the buffer portion is greater than a maximum width of the firstsolder.
 20. An OIS (Optical Image Stabilization) unit comprising; abase; a holder module comprising an outer blade spaced apart from thebase, a bobbin disposed in the outer blade, and a spring memberconnecting the outer blade and the bobbin; a first coil disposed on thebobbin; a magnet configured to interact with the first coil; and asecond coil configured to interact with the magnet.